1. Field of the Invention
This disclosure relates to the field of safety mechanisms for aerobic or cardiovascular exercise machines. In particular, to pull cord safety mechanisms for shutting off an exercise machine that utilize a captive cord.
2. Description of the Related Art
The benefits of regular aerobic exercise on individuals of any age are well documented in fitness science. Aerobic exercise can dramatically improve cardiac stamina and function, as well as lead to weight loss, increased metabolism, and other benefits. At the same time, aerobic exercise has often been linked to damaging effects, particularly to joints or similar structures, where the impact from many aerobic exercise activities can cause injury. Therefore, those involved in the exercise industry are continuously seeking ways to provide users with exercises that have all the benefits of aerobic exercise, without the damaging side effects.
In order to provide lower impact exercise, many individuals work out using an exercise machine. These machines have a number of advantages for performing exercise. In a first instance, they allow for aerobic exercise to be performed indoors in a relatively small space. They can also provide for an aerobic exercise with less damaging side effects. For example, in walking or running the impact of the person's foot with the surface produced by running on a road can be reduced by exercising on a treadmill. The treadbase of a treadmill can be purposefully engineered to absorb and reduce impact from footfalls, making the motion produce less impact on the body than a hard surface such as asphalt.
While the benefits of low impact exercise can be seen on a treadmill, they can be seen even more dramatically when other types of aerobic exercise machines are considered. Many types of machines, such as elliptical trainers, provide for a very low-impact exercise because they allow for the user to exercise using a motion which is not obtainable outside the machine and which is very low impact as it is a smooth motion with little to no impact ever occurring. The motion of these machines can be considered more beneficial than more traditional exercises in many respects, but the comparison is not really apt as the standing foot “pedaling” motion of an elliptical trainer is a motion that requires a machine to perform. This motion cannot be performed without benefit of a machine as the motion is not a “natural” motion, even though it is one that is comfortable to perform. Thus, the machine actually provides a completely new form of exercise unobtainable elsewhere.
Virtually all modern cardiovascular exercise machines produce exercise through the use of mechanical drive and/or resistance mechanisms and the vast majority include electric motors to produce some form of motion or resistance. For example, a modern treadmill will generally provide a motor to power a belt that produces a moving surface upon which the user “runs in place” to carry out the exercise. Even machines which do not include motors, often utilize mechanical constructs (such as brakes) controlled by control electronics to provide resistance to the user to make the exercise sufficiently difficult. Many also utilize mechanical, pneumatic, hydraulic or other components to produce incline. Exercise machines typically have a plethora of parts that are designed to move when the user is exercising. As such, exercise machines usually have a lot of powered moving parts when in use.
While this type of mechanical structure provides most of the benefit of an exercise machine, it can also present safety concerns. A motorized treadmill will move the belt whether or not a user is moving on it and should the user's motion cease, the movement of the belt can serve to push them (often quite rapidly) off the back of the treadbase. Safety concerns with exercise machines particularly relate to concerns when a user is using the machine and something happens so that their interaction with the machine changes. The biggest concern is the user becoming unstable on the machine and falling. In treadmills, for example, a user could land badly on a single step causing them to lose their balance and not be able to keep up with the moving belt for simply a matter of seconds. At high speed, continued belt movement can then cause them to fall or to be pushed off the machine or into its moving parts in a matter of seconds. Because of these problems, the vast majority of exercise machines (like most large electromechanical devices) provide an emergency electricity shutoff.
In exercise machines, the emergency shutoff is traditionally of one of two forms. Some exercise machines, like many industrial manufacturing machines, provide for a large emergency shutoff button. While this can be an effective mechanism, an emergency shutoff button is problematic for an exercise machine as the need for a shutoff will generally relate to a user being off-balance and moving in a somewhat uncontrolled fashion which can make it difficult for them to reach or activate the button in the short time before injury is potentially inflicted. They can also be out of range of the button due to the issue creating the safety concern. Because of this, most exercise machines usually utilize a shutoff key and pull cord.
A traditional shutoff key generally comprises a thin plastic wafer or other “key” which is slotted into a mating slot on the front panel of the exercise device and held in place by friction. When slotted, the key serves to move internal components of the treadmill which then creates an electric circuit between the electrical source, motor, and other electromechanical devices on the exercise device. Thus, the exercise device is “powered” when the key is in position in the slot as the electrical circuit from the power source (generally a wall outlet) to the motor and other electrically driven or controlled components is completed. The key is attached to a cord which is, in turn, connected to a clothing clip.
To use the exercise device, the user slides the key into the complimentary slot in the exercise device. When the key is so slotted, the exercise device has a complete circuit and is allowed to be powered. The user then is supposed to attach the clothing clip to their clothing and commences their exercise in a standard fashion. Because of the cord connection, should a user move away from the key slot further than the length of cord, their movement will generally overcome the inherent friction and pull the key from the exercise device. Removal of the key immediately breaks the electrical connections in the exercise device and forces it to shut off as the motor and other components immediately lose electric power.
As the key slots are generally positioned toward the front of the exercise device, a movement which will result in the cord being pulled is generally indicative of a person falling, moving backward, or otherwise not staying in the equilibrium position where the exercise is performed. Thus, should the user begin to fall, the machine will shut off and while the user may still fall (or may regain their balance) they will not fall into an operating machine.
Most safety keys are very simple and generally comprise a simple plastic shape that pushes two internal components into electrical connection internal to the machine, more advanced ideas have been proposed such as those described in U.S. Pat. Nos. 8,986,165 and 8,118,711, and United States Published Application 2009/0054208 the entire disclosures of which are herein incorporated by reference. Most traditional safety keys are not themselves conductive to avoid any need of electricity to pass through them, and they instead will mechanically move components internal to the control systems of the exercise device into electrical contact to complete the circuit. Even advanced safety keys, however, like all pull cord safety keys, suffer from certain similar problems.
In the first instance, the safety keys can get lost because they are separate components from the exercise machine itself. This can be frustrating to a user and can be a large problem at facilities such as gyms where multiple users share machines. It often means that people will commonly leave the key in the slot with the cord hanging loosely when they are done using the machine to avoid losing the key and not being able to operate the treadmill in the future. Some facilities will even tape or otherwise secure the keys so they cannot be easily removed. From this, it is easy for the user (or a new user) to simply forget to attach the cable to their clothing when the get on the treadmill because the key is generally not a particularly visually apparent object and the exercise machine is already in its powered state when the user arrives at it.
Further, many exercise machines utilize the key as their primary power switch with a main power switch, if present at all, being in a much less convenient location such as near the floor. Thus, a user leaving the key in the slot results in the exercise machine consuming unnecessary power as electronics remain powered up even when not in use. Instead, it is generally desirable for each user to remove the key after they are done using the exercise machine and place it in a convenient location. This insures that the next user must handle and insert the key both saving power in the interim and forcing the new user to handle the key reminding them they should attach the cord clip to their clothing before using the exercise machine.
Secondly, in order to allow the key to safely reach electrical components inside the control panel of the exercise machine while simultaneously avoiding a user being able to touch the electronic components or force another object into the key slot, many safety keys are actually quite long and are commonly generally rectilinear in shape. This shape means that there can be substantial friction and other problems to pull the key from the slot if it is being pulled at any angle other than essentially straight out. For example, most keys cannot be pulled from the slot by pulling the cord at an angle generally 90 degrees to the primary axis of the key in any dimension. As a fall or unbalancing event can readily cause the user to move in a direction that is not straight back and is often downward (which is generally around 90 degrees to the position of the key when inserted), in certain fall events the clothing clip can actually be pulled from the user's clothing more easily than the key can be pulled from the slot which results in the machine not shutting off and the safety key not meeting its intended purpose.